Method for removing dissolved oxygen from hydrocarbon gels

ABSTRACT

A method of removing dissolved atmospheric oxygen from hydrocarbon liquids and gels which comprises incorporating pyrogallol in the alkaline portion of a three-component flame fuel system consisting of an alkaline portion, a nonalkaline portion, and a hydrocarbon liquid portion. This method effectively reduces swelling of the product formed.

United States Patent Ken Posey, Jr.

Allen, Tex.

June 16, 1969 Nov. 16, 1971 The United States of America as representedby the Secretary of the Navy lnventor Appl. No. Filed Patented AssigneeMETHOD FOR REMOVING DISSOLVED OXYGEN [56] References Cited I UNITEDSTATES. PATENTS 3,414,392 12/1968 Pruitt 44/7 C OTHER REFERENCES Fieser& Fieser, Organic Chemistry," Third Edition, Reinhold Publ. Co., NewYork, 1956, p. 631 [0D, 251, F5, 1956] Primary Examiner-Benjamin R.Padgett Atrorneys- Edgar J. Brower and Roy Miller ABSTRACT: A method ofremoving dissolved atmospheric oxygen from hydrocarbon liquids and gelswhich comprises incorporating py'rogallol in the alkaline portion of athree-component flame fuel system consisting of an alkaline portion, anonalkaline portion, and a hydrocarbon liquid portion. This methodeffectively reduces swelling of the product formed.

METHOD FOR REMOVING DISSOLVED OXYGEN FROM HYDROCARBON GEIS BACKGROUND OFTHE INVENTION The present invention relates to a method of effectivelyreducing the swelling of gelled hydrocarbon flame fuels by removingdissolved atmospheric oxygen therefrom.

Liquid hydrocarbon may be desirably thickened or converted to gels whichare useful in the making of incendiaries and the like. Dissolvedatmospheric oxygen in hydrocarbon liquids and gels has created someundesirable effects such as swellingand foaming due to the formation andgrowth of gas bubbles throughout the liquids or gels. Hydrocarbon gelsswell in a manner similar to rising bread dough and as a result of thisswelling bombs or other devices filled with gel overflow decreasingtheir effective capacity. In sealed containers, pressures sufficient tocause rupture may develop. Also the overflow causes safety andhousekeeping problems. The present invention alleviates the swellingproblem by adding pyrogallol during the processing of the flame fuelgel.

SUMMARY OF THE IN VENTION This invention relates to a method forremoving dissolved atmospheric oxygen from hydrocarbon liquids and gelsthereby reducing postgel swelling which often occurs.

It is the general purpose of this invention to provide an improved flamefuel gel for use in incendiary bombs and other similar devices. Anotherobject is to improve the usefulness of hydrocarbon gels by a methodwhich alleviates swelling, (which is more pronounced when the ambienttemperature rises) thereby increasing the effective capacity of bombs orother devices and decreasing the safety hazard and housekeepingproblems.

DESCRIPTION OF THE INVENTION The invention resides in the discovery thatpyrogallol incorporated during the processing of a flame fuel gelalleviates swelling of the gel by removing dissolved oxygen therefrom.The fuel gel comprises three components: an alkaline solution, anonalkaline solution, and a hydrocarbon liquid and is better describedin U.S. Pat. No. 3,414,392 which issued 3 Dec. 1968. The method,briefly, comprises adding pyrogallol in a concentration of about 0.80percent to the alkaline solution which consists essentially of sodiumhydroxide, potassium hydroxide and water. At the time the above ismixed, the nonalkaline portion consisting essentially of linoleic acidand oleic acid was mixed with a liquid hydrocarbon consisting ofaviation gasoline or turbine fuel. The alkaline portion containingpyrogallol was then mixed with the fuel and nonalkaline mixture to formthe gel described in the above-cited U.S. patent.

The following ingredients are representative of the three componentgelled fuel:

Nonalkaline Solution (A) Ingredients Parts by weight Blend of organicacids 79-81 A dispersant 19-21 Alkaline Solution (B) Ingredients Partsby weight Sodium hydroxide 28.5-30.5

Potassium hydroxide 15.9-17.8 Pyrogallol 00.770.80 Water 5483-509 tomake a total of 100.0 1 1.00 parts Hydrocarbon Liquid (C) Aviationgasoline Turbine fuel (IP 4 and .lP-5) The acid blend of group A wasmixed with the dispersant according to the art of U.S. Pat. No.3,414,392 and 7.2 ml. were added to 150 ml. of turbine fuel from group Cand thoroughly mixed.

The alkaline solution from group B was prepared as follows: 0.77 to 0.80parts by weight pyrogallol was dissolved in 1.97 to 2.05 parts by weightof water. The pyrogallol addition was then thoroughly mixed with thealkali solution consisting of 28.50 to 30.5 parts of sodium hydroxideand 15.9 to 17.8 parts potassium hydroxide and water to make parts byweight in a container from which air has been replaced with nitrogen.

The gel of U.S. Pat. No. 3,414,392 was prepared with the aboveingredients by a convenient laboratory technique. The acid-fuel mixtureconsisting of liquid fuel (C) and nonalkaline solution (A) was poureddownthe inside wall of the container containing alkaline solution (B) sothat the acid-fuel mixture formed a separate layer on top of solution(B). Sufficient acidfuel mixture was added to completely fill thecontainer and thereby exclude atmospheric oxygen. The three componentswere then vigorously mixed until gelation occurred in about 15 seconds.The gel possessed excellent consistency and stringiness characteristicsand exhibited a marked reduction in swelling over gels prepared with theusual ingredients.

Pyrogallol in a concentration of 0.08 percent in the alkaline solutionas described herein effectively reduces hydrocarbon gel swelling.Pyrogallol is very active to oxygen in alkaline conditions but reactsslowly in acid or neutral medium.

Because pyrogallol absorbs oxygen from air (and thus has its oxygenabsorbing capacity depleted) suitable precautions should be taken duringmixing and filling operations to minimize contact ofpyrogallol-containing solutions with air. Strength of the solution shallbe preserved by replacing any air in contact with the alkaline solutionwith nitrogen. Since pyrogallol dissolves with difficulty inconcentrated alkali solution, it is desirable to first dissolve thepyrogallol in water. Any such pyrogallol addition should then bethoroughly mixed with the alkali solution in a container from which theair has been replaced with nitrogen.

The alkaline component (B) may be made from commercial grade causticsoda, caustic potash and pyrogallol. It may be produced either fromsolid chemicals, or from solutions of the solid chemicals, or from anycombination of these.

The nonalkaline component (A) is a blend of organic fatty acids and adispersant. The fatty acid portion is comprised of a mixture of fattyacids with an acid value greater than 195 and less than 202, an iodinevalue greater than and less than 146, a liter of 41 F. or lower, and afatty acid distribution approximating 60 percent of linoleic acid, 32percent of oleic acid, 3 percent of other unsaturated acids, 5 percentof saturatedfatty acids, and minor constituents. The fatty acid portionis commercially available as Neofat and Emersol 3 10.

The dispersant is composed principally of an addition product ofethylene oxide and technical dehydroabiethylamine (containing 5 moles ofreacted ethylene oxide per mole of dehydroabiethylamine). Approximately15 percent by weight unsubstituted technical dehydroabiethylamineaccompanies the ethyoxylated portion. The above mixture is dissolved togive a 70 percent by weight solution in isopropyl alcohol. This materialis commercially available as Polyrad 0515A.

Experimentally it was found to be expedient to accelerate and amplifythe swelling tendency of gels by raising their temperature by 30 F. Theamount of volume expansion per degree Fahrenheit was used to compare therelative swelling characteristics of various gels. The comparison ofexpansion per degree Fahrenheit was made of the present aviationgasoline gel (with pyrogallol) and the regular aviation gasoline gel(without pyrogallol) with the following results:

*2 Expansion per Degree Fahrenheit Sample Description Regular gel 1Regular gel ll 0.180 Regular gel Ill 0210 Regular gel IV 0.2 l Gel withpyrogallol I 0.04] Gel with pyrogallol ll 0.045 Gel with pryogallol lll0.036 Gel with pyrogallol lV 0.046

turbine fuel, said method comprising first incorporating pyrogallol insaid alkaline solution; then mixing said alkaline-pyrogallol solutionwith said nonalkaline solution and hydrocarbon fuel.

2. The method in accordance with claim 1 wherein the concentration ofpyrogallol in said alkaline solution is about 0.80 percent.

3. A flame fuel comprising a hydrocarbon fuel selected from the groupconsisting of aviation fuel and turbine fuel bound in a matrixcomprising the reaction product obtained by mixing gelling proportionsof an alkaline solution consisting essentially of an aqueous solution ofsodium hydroxide, potassium hydroxide and pyrogallol and a nonalkalinesolution consisting essentially of unsaturated fatty acids and adispersant composed of ethylene oxide and dehydroabiethylamine.

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2. The method in accordance with claim 1 wherein the concentration ofpyrogallol in said alkaline solution is about 0.80 percent.
 3. A flamefuel comprising a hydrocarbon fuel selected from the group consisting ofaviation fuel and turbine fuel bound in a matrix comprising the reactionproduct obtained by mixing gelling proportions of an alkaline solutionconsisting essentially of an aqueous solution of sodium hydroxide,potassium hydroxide and pyrogallol and a nonalkaline solution consistingessentially of unsaturated fatty acids and a dispersant composed ofethylene oxide and dehydroabiethylamine.